This volume contains the proceedings of the Seventh IFIP WG 6.1 International Conference on Distributed Applications and Interoperable Systems (DAIS 2007) held in Paphos, Cyprus, June, 6-8, 2007. Distributed applications and interoperable systems have become an integral part of everyday living, part of the socio-economic ecosystem of our human environment. With such interdependence between society and software, distributed software applications must be sustainable and adaptable in the long term, despite the changes in our environment. Therefore, the theme of DAIS 2007 was ''Towards Sustainability'' and the papers of DAIS2007 addressed the following questions:– How do we ensure our distributed applications can make local adaptation to specific circumstances of their deployment?– How do we make our interoperable systems evolvable in the face of widespread change in their environment?– How do we integrate distributed software within the wider fabric of computing within our modern world?